Testate amoebae assemblages from soils in the Zackenberg area, Northeast Greenland

Testate amoebae communities across five different,vegetation and soil types in a coastal region of Northeast Greenland were studied, in order to understand the distribution of these organisms with respect to habitat properties in this extreme environment. Thirty-eight taxa representing 12 genera were observed in 39 samples, About 43% of the testate amoebae belonged to a single species: Trinema lineare. Difflugia globulus and Centropyxis acrophila var. sphagnicola showed also high relative abundances. Average shelf density/g dry weight was 35,000 +/- 21,000. Hierarchic-agglomerate classification revealed three assemblages. A Difflugia globulus-Centropyxis aerophila var. soil from the Arctagrostis and Vaccinium vegetation type. This assemblage was associated with higher soil moisture content and a thicker active layer. The Celltropyxis aerophila-Trinema complanatum assemblage, that was found in the soils beneath the Cassiope and Salix vegetation, was associated with lower soil moisture content. The assemblage found in soils beneath the Poa vegetation type was characterized by Trinema lineare and Euglypha rotunda and was associated with high organic content of the soils and a shallower active layer. These results, suggest that testate amoebae assemblages are ecologically distinct across short distances in the high arctic soil habitats.